Question

помогите пожалуйста​

Answer 1

А)

$1 frac{4}{5} - frac{9}{10} = 1 frac{4 times 2}{5 times 2} - frac{9}{10} = 1 frac{8}{10} - frac{9}{10} = frac{10 + 8}{10} - frac{9}{10} = frac{18}{10} - frac{9}{10} = frac{9}{10}$

Б)

$frac{7}{24} + frac{5}{24} = frac{12}{24} = frac{12 div 12}{24 div 12} = frac{1}{2}$

В)

$frac{17}{18} - frac{5}{18} = frac{12}{18} = frac{12 div 6}{18 div 6} = frac{2}{3}$